1. Field
The present disclosure relates to a polymer electrolyte for a lithium battery and a lithium battery including the polymer electrolyte.
2. Description of the Related Art
Conventionally, a carbonate organic electrolyte, such as an ethylene carbonate or a propylene carbonate, has been used as an electrolyte for a lithium battery. However, the carbonate organic electrolyte has a high risk of leakage, and therefore, may present a safety issue, such as an explosion. In order to solve this problem, a solid electrolyte, such as polyethylene oxide (PEO), may be used in a lithium battery instead.
However, in a lithium metal battery (in particular, lithium air battery), PEO may decompose at high voltage. Since charging and discharging of a lithium air battery involves applying high voltage, it has been established that when the PEO contacts oxygen provided from a positive electrode, free radicals are produced, the PEO is oxidized, the polymer is dissociated, and a by-product carbon dioxide is formed as a result. A lifespan of such a lithium air battery becomes reduced, and thus, the battery becomes impractical. Thus there remains a need in a novel electrolyte that is stable at high voltage and has excellent mechanical properties.